This invention relates to an automatic taping apparatus for winding automatically a tape-shaped material around a long body including not only straight portions but also curved portions.
Upon winding the tape-shaped material around long bodies having the substantially uniform cross section throughout their length after having been bent into complicated shapes, the substantial portion of the taping operation has previously relied on human power and automated machines therefor have been practically employed only with the straight portions of such bodies. In other words, those automated machines have been only employed in taping simple shapes. Also it has been sometimes practiced to secure a taping machine to an associated body to be taped such as a coil and tape the body while keeping the direction of the machine coinciding with that of the body.
Therefore the so-called automatic taping apparatus have not been previously generalized in the field of the tape winding technique. In view of the latest progress of numerical machine-tool control systems, it may be expected to apply those control systems to taping apparatus.
The description will now be briefly made in conjunction with the operating procedure of numerical control machine tools. First, it is required to look over the manufacturing drawings specified for the particular workpiece to prepare numerical expressions describing loci along which control elements of an associated machine tool are destined to travel. For example, if the workpiece should be machined into a straight shape, the numerical expressions may be of the first order. On the other hand, higher order expressions are required for machining the workpiece into a curved shape. Alternatively, one may read out coordinates of several points on each of the loci referring to the particular three-dimensional orthogonal coordinate system. Then the numerical expressions or read data enter a large-scaled digital computer where each of the loci is divided into a multiplicity of plots each having a minute length of a few tenths of one millimeter or a few millimeters and a speed of movement of each control element of the machine tool in each plot is calculated with respect to a different one of control axes or X, Y and Z axes of the three-dimensional orthogonal coordinate system from X, Y and Z coordinates of the plots. If the machine tool is of an arm structure rotatable about a predetermined point then it is advantageous to transform the three-dimensional orthogonal coordinate system to a three-dimensional polar coordinate system including two angular coordinates and a radial coordinate. The digital computer may automatically perform this operation of transformation through the utilization of an automactic program such as an "APT" (which is the abbreviation for an "automatic programming tool") prepared to be generally used for this purpose.
Command position or movement values for the incremental minute plots calculated by the digital computer as above described are successively delivered to a paper tape and punched on the latter. Then the punched paper tape is passed through a tape reader included in a numerical control mechanism for the machine tool thereby to enter the command values into the machine tool.
On the other hand, the machine tool responds to data written in the paper tape to control each of the control elements with respect to the control axes to travel orderly and successively toward the minute plots one after another with predetermined incremental time intervals. This results in each control element of the machine tool traveling along the associated locus first read out from the manufacturing drawings.
It is summarized that, from the numerical expressions describing the loci for command traveling points read out from the manufacturing drawings the large-scaled digital computer calculates a command position or movement value for each of the minute plots and for each of the control elements after which the associated numerical control type machine tool is operated in resposes to the command values entered thereinto.
However, upon applying the numerical machine tool control system as above described to taping apparatus, the various disadvantages are caused. A first one of the disadvantages is the necessity of transferring an enormous quantity of numerical data calculated by a large-scaled digital computer to a taping apparatus involved. A second one thereof is the fact that bodies to be taped are curved. More specifically, the curved bodies are not, in many cases, completed substantially as described in the manufacturing drawings involved. Similarly, bodies to be taped and which are manufactured in accordance with the same manufacturing drawings are more or less different from one to another thereof. This results in the necessity of preparing control data for each of the bodies to be taped which is inevitably attended with a troublesome procedure of measuring a shape of each of the bodies after the completion of its bending operation, preparing control data for each of the measured bodies by operating a large-scaled digital computer and transferring the control data to the taping apparatus.
Accordingly it is an object of the present invention to provide a new and improved automatic taping apparatus operative in simple manner by itself without using a large-scaled digital computer and also without preparing an enormous quantity of command control values for individual minute plots on a body to be taped and for respective control elements.